Liu Chuanwang, Huo Yanman, Bu Jiawei, Yuan Zhaoran, Liang Kangjiang, Xia Chengfeng
Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, China.
J Org Chem. 2024 Aug 2;89(15):10805-10815. doi: 10.1021/acs.joc.4c01061. Epub 2024 Jul 15.
Perfluoroalkyl iodides generally formed electron donor-acceptor (EDA) complexes by halogen bonding with a nitrogen atom containing Lewis bases. Since the electronegativity of the oxygen atom is stronger than that of the nitrogen atom, the resulting Rf-I···O-type halogen bonding EDA complex is less inclined to undergo electron transfer. Here, we reported rare ternary EDA complexes among perfluoroalkyl iodide, oxygen atom, and base. Mechanism experiments and density functional theory theoretical (DFT) calculations indicated that a base-promoted proton-coupled electron transfer (PCET) process was involved in this photochemical reaction. The intracomplex electron transfer event generated two radical species, perfluoroalkyl radical and TEMPO radical, enabling the subsequent oxy-perfluoroalkylation of olefins.
全氟烷基碘化物通常通过与含氮原子的路易斯碱形成卤键来形成电子供体-受体（EDA）配合物。由于氧原子的电负性强于氮原子，因此生成的Rf-I···O型卤键EDA配合物不太容易发生电子转移。在此，我们报道了全氟烷基碘化物、氧原子和碱之间罕见的三元EDA配合物。机理实验和密度泛函理论（DFT）计算表明，该光化学反应涉及碱促进的质子耦合电子转移（PCET）过程。配合物内的电子转移事件产生了两种自由基物种，即全氟烷基自由基和TEMPO自由基，从而实现了烯烃随后的氧-全氟烷基化反应。
